SPEED MEASUREMENT SYSTEMS WORLD PULP&PAPER 14 Speed measurements on paper machines are essential to get to the root of increased fabric wear or sheet breaks. Heimbach’s TASK (Technical Assistance, Service and Know-How) department assists the company’s customers in numerous ways. Whether they are investigating one or, in some cases, all sections of a paper machine, offering advice on machine technology or performing analyses, no two jobs are alike. One thing TASK does know for sure: a customer first needs to be in possession of the facts in order to pursue a line of enquiry. And TASK is able to help with specific measurement technology. In this particular case, a customer By Thomas Fischer, Manager Technical Service, Heimbach GmbH & Co. KG Getting your paper machine up to the right speed using the right measurements - a case study a customer first needs to be in possession of the facts in order to pursue a line of enquiry had ordered the complete clothing package from Heimbach and had requested TASK to check the jet- wire speed. The TASK team was in action during the start-up phase of a machine producing folding boxboard and carried out measurements on three headboxes in order to assess the jet-wire ratio. MEASUREMENTS ARE COMPLEX There are often jobs in which speed measurement results helped to determine the cause of increased fabric wear and/or disproportionately increased sheet breaks. Other jobs consist of precision-tuning drive systems or synchronising transfer positions. In addition to this, TASK frequently checks machine settings, such as speed indicators, for accuracy – and this was also relevant for this particular assignment. FACTS FOR FORMING Once on site, the Heimbach engineers exchanged views with the production manager who suspected that the three fabrics were not running at exactly the same speed, which could lead to displacement or movement of the sheet layers during couching. Furthermore it wasn’t at all clear whether jet speeds were displayed correctly in the control room, which for machine operators in the forming section is the control instrument per se – after all, they rely on correct data in the control room to make the necessary adjustments at the machine. Figure 1. Fabric speed in the filler as well as surface and back layers.